title: Comparative effectiveness of osteoporosis drugs in preventing secondary nonvertebral fractures in Taiwanese women.
abstract: BACKGROUND
  The evidence for relative effectiveness of osteoporosis drugs in secondary prevention of nonvertebral fractures was unclear and could not be extrapolated to the Asian population.
  
  
  OBJECTIVE
  The objective of the study was to compare the relative effectiveness of different classes of osteoporosis drugs in secondary prevention of nonvertebral fractures in Taiwanese women.
  
  
  METHODS
  This was a retrospective cohort study from 2003 to 2007, with up to 6 years of follow-up.
  
  
  METHODS
  The study included enrollees in Taiwan National Health Insurance.
  
  
  METHODS
  Patients older than 50 years, with vertebral/hip fracture and were new to osteoporosis therapy, were recruited.
  
  
  METHODS
  Patients were classified into the alendronate, calcitonin, or raloxifene group, according to their exposure after follow-up.
  
  
  METHODS
  The primary outcome of our study was the risk of incident nonvertebral fracture (hip, humerus, or radius fractures). A multivariate Cox proportional hazard model adjusted for fracture risk factors was used to compare the relative fracture risk among three treatment groups under on-treatment scenarios. Propensity score-matched hazard ratios were examined, and interactions between fracture incidence and patients' compliance were investigated as well.
  
  
  RESULTS
  There were 19 840, 9534, and 25 483 patients in the alendronate, raloxifene, and calcitonin groups, respectively. The fracture rates were highest in calcitonin recipients (4.57 per 100 person-years), followed by raloxifene and alendronate. Results from Cox analyses showed raloxifene (hazard ratio 1.47; 95% confidence interval 1.29-1.67) and calcitonin (hazard ratio 1.51; 95% confidence interval 1.29-1.75) had higher nonvertebral fracture risks as compared with alendronate. The risk differences were more pronounced in compliant patients.
  
  
  CONCLUSIONS
  We found alendronate users had the lowest secondary nonvertebral fracture risk, as compared with raloxifene and calcitonin users. Consistent results were found in a series of sensitivity analyses.
authors.affiliation: BS Pharm, Institute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, University Road, Tainan, 70101, Taiwan. yhkao@mail.ncku.edu.tw.
authors.forename: Tzu-Chieh
authors.initials: TC
authors.lastname: Lin
authors.forename: Chyun-Yu
authors.initials: CY
authors.lastname: Yang
authors.forename: Yea-Huei Kao
authors.initials: YH
authors.lastname: Yang
authors.forename: Swu-Jane
authors.initials: SJ
authors.lastname: Lin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D002116:Calcitonin / Q000627:therapeutic use*; D016022:Case-Control Studies; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D055118:Medication Adherence; D008875:Middle Aged; D009313:National Health Programs; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000208:ethnology; D058866:Osteoporotic Fractures / Q000453:epidemiology / Q000208:ethnology / Q000517:prevention & control*; D016016:Proportional Hazards Models; D020849:Raloxifene Hydrochloride / Q000627:therapeutic use*; D012189:Retrospective Studies; D055502:Secondary Prevention; D013624:Taiwan / Q000453:epidemiology
chemical_list: D050071:Bone Density Conservation Agents; D020849:Raloxifene Hydrochloride; D002116:Calcitonin; D019386:Alendronate